Beginning in childhood, African Americans have higher blood pressure (BP) levels than whites. In a recent analysis by our group, African Americans without hypertension at 45 years of age had > 90% lifetime risk for developing incident hypertension. Further, African Americans treated with antihypertensive medications are less likely to achieve guideline recommended BP levels when compared to whites on antihypertensive medications. The health care implications associated with hypertension in African Americans are profound; hypertension is a strong risk factor for stroke, heart failure, and end-stage renal disease (ESRD), conditions that occur more frequently among African Americans than whites. In this application, we propose to incorporate a Hypertension Working Group into the Jackson Heart Study (JHS-HWG). Four thematic areas of investigation are proposed: 1. Risk factors for incident hypertension; 2. BP phenotypes using 24 hour ambulatory BP monitoring (ABPM); 3. Uncontrolled treated hypertension including treatment resistant hypertension; and 4. Medication adherence. As the dysregulations underlying hypertension and BP control in African American are complex and likely multi-dimensional, we propose a multi- disciplinary team of investigators with complementary expertise in hypertension, health disparities, psychosocial health, epidemiology, biostatistics, and clinical cardiology. The JHS is an ideal population-based study to further our understanding of BP issues in African Americans. JHS enrolled 5,301 African Americans in 2000-2004 and data were collected on medication use and adherence, sub-clinical atherosclerosis measures, psychosocial variables, and blood and urine biomarkers during three study visits at 4 year intervals. Participants are being actively followed for the occurrence of clinical outcomes (e.g., coronary heart disease, hospitalized heart failure, and stroke). Additionally, ABPM was conducted at baseline in a sub-sample of 1,076 JHS participants, making this one of the largest population-based studies with ABPM in the US. ABPM can be used to estimate BP variability and diurnal BP, and diagnose white coat and masked hypertension, emerging cardiovascular disease risk factors that are understudied in African Americans. Another primary objective of the JHS - HWG will be to provide mentorship to early stage investigators (ESIs), with a special emphasis on under-represented researchers. This will include having ESIs lead JHS writing groups and JHS ancillary grant applications, to aid in their transition towards independence. The ESIs included in this application were chosen for their research potential, interest in minority health and the thematic areas in the application The principal investigators, who have an excellent track record of mentorship, will also be supported by an Advisory Committee and expert panel of Senior Faculty Mentors, who all have a strong history of mentorship as well as research productivity in minority health and hypertension-related areas. Finally, we plan to submit ancillary studies to JHS that make the JHS-HWG self-sustaining beyond the funding period.